solar system physics i dr martin hendry 5 lectures, beginning autumn 2007
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Department of Physics and Astronomy Astronomy 1X Session 2007-08. Solar System Physics I Dr Martin Hendry 5 lectures, beginning Autumn 2007. [email protected]. Course information and handouts: access via A1X moodle site http://moodle.gla.ac.uk/physics/moodle/. - PowerPoint PPT PresentationTRANSCRIPT
Solar System Physics ISolar System Physics IDr Martin Hendry
5 lectures, beginning Autumn 2007
Department of Physics and Astronomy
Astronomy 1XSession 2007-08
Course information and handouts: access via A1X moodle site
http://moodle.gla.ac.uk/physics/moodle/
Use your novell ID and password
You will also need the A1 enrolment key
orion
Missed A1X enrolment on Wed 19th?...
Come to see me at the end of today’s lecture
Still to register on A1X moodle?...
Course Textbook available as a special package from the University Bookshop:
Includes additional chapters from Carroll & Ostlie whichare essential to A1X,Y
Cost £49.99Includes access to online learning resources forAstronomy Today
www.coursecompass.comcourse ID:
hendry35396
Astronomy A1X 2007-08Solar System Physics I – Lecture Plan
Introductory Tour of the Solar Systemo Qualitative description of the Sun, planets, moons and minor bodies, contrasting Jovian and terrestrial planetso Some Solar System vital statisticso Overview of Solar System formation
Gravitation and Solar System physicso Newton’s law of gravitationo Surface gravity and escape speedo Tidal forces
2 le
ctur
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Links to A1X Dynamical Astronomy
Astronomy A1X 2007-08Solar System Physics I – Lecture Plan
The physics of planetary atmosphereso The ideal gas law and velocity of gaseso Hydrostatic equilibrium and atmospheric scale heights
The Jovian planets and their moonso Internal and atmospheric structure and compositiono Ring systems and Roche stabilityo Physical properties of the main satelliteso Case study: the Galilean moons
3 le
ctur
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Astronomers have studied the motions of the Sun, Moon and planets for thousands of years (see A1X Positional Astronomy)
Section 1: A Tour of the Solar System
Some vital statistics:- The Solar System consists of:-
o the Sun, o its 8 planets,o their moons,o dwarf planets, asteroids and comets,o the ‘Solar wind’
Retrograde motion
Astronomers have studied the motions of the Sun, Moon and planets for thousands of years (see A1X Positional Astronomy)
Before the invention of the telescope, however, we knew almost nothing about their true nature.
Section 1: A Tour of the Solar System
Some vital statistics:- The Solar System consists of:-
o the Sun, o its 8 planets,o their moons,o dwarf planets, asteroids and comets,o the ‘Solar wind’
Galileo Galilei:(1564 – 1642)
The Observations of GalileoThe Observations of Galileo
Geocentric model Heliocentric model Sun
Sun
The Observations of GalileoThe Observations of GalileoIn 1609 Galileo observed phases of Venus
The Observations of GalileoThe Observations of Galileo
Phases of Venus impossible to explain in geocentric model
Clear evidence that the Earth went round the Sun, and not the other way round
The Sun: some vital statistics:
The Sun is a star: a ball of (mainly) hydrogen gas, 700,000 km in radius (about 100 Earth radii)
.
Earth, to scale
The Sun: some vital statistics:
The Sun is a star: a ball of (mainly) hydrogen gas, 700,000 km in radius (about 100 Earth radii)
It generates heat and light through nuclear fusion:Surface temperature = 5800KCentral temperature = ~15 million K
Balance (hydrostatic equilibrium) maintained between pressure and gravity
Hydrogen fusion – fuelling a star’s nuclear furnace
E = mc 2
H = HydrogenHe = Helium
The Sun: some vital statistics:
The Sun is a star: a ball of (mainly) hydrogen gas, 700,000 km in radius (about 100 Earth radii)
It generates heat and light through nuclear fusion:Surface temperature = 5800KCentral temperature = ~15 million K
Balance (hydrostatic equilibrium) maintained between pressure and gravity
The Sun’s outer atmosphere, or corona, is very hot (several million K) – heated by twisting of the Sun’s magnetic field
Earth’s magnetic field
Magnetic fieldson the sun
Section 1: A Tour of the Solar System
The Planets: some vital statistics:-
Name Diameter* (Earth=1) Mass (Earth=1) Mean distance from the Sun
4880 km (0.383)
12104 km (0.949)
12756 km (1.000)
6794 km (0.533)
* Equatorial diameter
142984 km (11.209)
120536 km (9.449)
51118 km (4.007)
49528 km (3.883)
~2300 km (0.18)
kg10974.5 24 (1.000)
kg10302.3 23 (0.055)
kg10869.4 24 (0.815)
kg10418.6 23 (0.107)
kg10899.1 27 (317.8)
kg10685.5 26 (95.16)
kg10682.8 25 (14.53)
kg10024.1 26 (17.15)
kg103.1 22 (0.0021)
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
km1079.5 7 (0.387 AU)
km10082.1 8 (0.723 AU)
km10496.1 8 (1.000 AU)
km10279.2 8 (1.524 AU)
km10783.7 8 (5.203 AU)
km10432.1 9 (9.572 AU)
km10871.2 9
km10498.4 9
(19.194 AU)
(30.066 AU)
km10915.5 9 (39.537 AU)
See also table 6.1 in Astronomy Today
Mean Earth – Sun distance = Astronomical UnitAstronomical Unit
149,597,870 km
1 A.U. = 107 solar diametersThe orbits of the planets are ellipses and lie in, or close to, a plane – the ecliptic. (See A1X Dynamical Astronomy).
Mean Earth – Sun distance = Astronomical UnitAstronomical Unit
149,597,870 km
1 A.U. = 107 solar diametersThe orbits of the planets are ellipses and lie in, or close to, a plane – the ecliptic. (See A1X Dynamical Astronomy).
The planets divide into two groups:Inner Terrestrial planets: small, rocky
Outer Jovian planets: gas giants
Mercury, Venus,Earth, Mars
Jupiter, Saturn, Uranus, Neptune
Mars 2004:Mars 2004: Mars Express ( + Beagle 2) Spirit + Opportunity
January 2004:
Mars Express Orbiter detects water ice at the South Pole of Mars.
H2O CO2 Visible light
Inside Europa
Could there be life?…..
Mean Earth – Sun distance = Astronomical UnitAstronomical Unit
149,597,870 km
1 A.U. = 107 solar diametersThe orbits of the planets are ellipses and lie in, or close to, a plane – the ecliptic. (See A1X Dynamical Astronomy).
The planets divide into two groups:Inner Terrestrial planets: small, rocky
Outer Jovian planets: gas giants
Pluto is a ‘misfit’ – Kuiper Belt object; along with asteroids and comets, ‘debris’ from formation of the Solar System.
Mercury, Venus,Earth, Mars
Jupiter, Saturn, Uranus, Neptune
Invention of telescope led to discovery of Minor Planets or asteroids. Most orbit between Mars and Jupiter – Asteroid Belt
‘Lumps’ of rock (up to 1000km across), reflecting sunlight. Only visible through a telescope
Leonid Meteor Shower: Nov 17Leonid Meteor Shower: Nov 17thth – 18 – 18thth
873 years till 873 years till Doomsday?…Doomsday?…
Credit: Arecibo Observatory
Asteroid 1950DA: 1 in 300 chance of collision with Earth on March 16th 2880(Science, Apr 5th 2002)
1.1km
Need to determine the orbit of the asteroid……all about gravity